Adventures of an Aviatrix, in which a pilot travels the skies and the treacherous career path of Canadian commercial aviation, gaining knowledge and experience without losing her step, her licence, or her sense of humour.

Friday, August 23, 2013

The Moral of the Story

I'm sure many readers of this blog already follow Randall Munroe's xkcd ("A webcomic of romance, sarcasm, math, and language,") but not everyone knows about his side projects, like his what-if blog. In it he answers questions of life, the universe and everything, such as "could an airplane fly in the atmospheres of other planets?" His answers tend to be both amusing and comprehensive, plus you don't need any math to understand the pictures illustrating the calculated success of flights on the various bodies of our solar system.

Turns out Titan is our best bet. It would be even easier to fly there, but too cold. Cold, Randall points out is merely a materials science problem. He says, "I've never seen the Icarus story as a lesson about the limitations of humans. I see it as a lesson about the limitations of wax as an adhesive." Yes, Randall, yes. So many stories ask me to accept baffling morals.

I more than once got in trouble in English class for laughing at stories that were supposed to be sad, or just being plain baffled as to why the story ended where it did. Shadow of a Gunman features a young women infatuated with a writer. She asks him to typewrite their names together on a scrap of paper and later protects him during a raid by hiding contraband that he in her room. At the end of the story she has been arrested, then shot dead while attempting to escape custody. A neighbour reports this, saying that the police found a scrap of paper in her breast with her name on it, and someone else's name, all covered in blood. I howled with laughter right there in class and when I explained that I liked the irony that she thought she was protecting him, but really she has condemned him by keeping that paper. The English teacher patiently explained that her blood had obscured the name, so she had protected him, and the teacher refused to accept that the most basic of 1920s police procedure would be able to read typewriter ink despite blood. I believe I challenged her to bleed so profusely on a piece of paper that I could not distinguish typewritten words using merely tools I could prove existed in 1920. I never considered it a bad thing to be kicked out of that English class.

Romeo and Juliette is another one. How is that not a hilarious lesson on the stupidity of overly dramatic teens? Or the story about the woman who sells her hair to buy a watch chain for her lover, who sells his watch to buy a jewelled hair comb for her. A lesson for all on basic communication in a relationship. And her hair will grow back. Rudolph the Red-Nosed Reindeer teaches us that it's okay to mock and exclude someone for being different up until the point that that difference is proven to have a material benefit to us, at which point we can do an about-face. An earlier version of Goldilocks and the Three Bears ended with the titular intruder (then a silver-haired old woman) impaled on a church steeple for her crimes, but now I could think I was supposed to believe it's about not giving up until you've found something that's just right, and running away if anyone questions your right to it.

Sometimes the story doesn't support the moral, but if the story itself is well told, then people accept the moral they are fed. How about this TSB accident report. (Hah, yu thought I'd wandered so far off aviation I was never coming back, didn't you?) Normally I love the attention to detail and the simple laying out of discovered facts in an accident report. Nothing is pushed on you. You can see what they found, what occurrences the experts find it consistent with and pretty much draw your own conclusions. While it is quite startling to see the altitude deviations correlated with the pilot talking on the phone and sending text messages, I think this accident was more a convenient place to hang the "no cellphone use during flight" message than it was a demonstration of the dangers thereof. Read it and don't you get the idea that the TSB considers the cellphone use a bigger deal than the fact that the pilot was flying at night for a company not certified to do so, and therefore with no recent night-specific training and quite likely no recent night experience? My company hung the cellphone message on this accident, too: the preliminary report year or so ago was the trigger for my own company's ban on pilot cellphone use during flight. Oh well, I could never get Facebook check-ins to work at 15,000', anyway.

A moral that doesn't match the story isn't necessarily a bad moral, and a story with a mismatched moral isn't necessarily a bad story, I just feel like someone is trying to cheat me when I encounter the combination. Also, the air gets cooler the closer you get to the sun until well after the altitude at which Icarus would have asphyxiated.

I read the accident reports about once a month. It sort of hammers home how situations can get out of hand or how small oversights compound into larger problems. I know the gist of the post was something else, but it all ties together quite nicely.

Just to be clear, Romeo and Juliet is exactly a story of how teens take their infatuations completely out of proportion. It is only the modern (20th century and later) reading that turned it into a "perfect, innocent love story".

The Icarus story should really be re-told with modern aviation. Perhaps Daedalus rigs up a home-made ultralight, and warns Icarus of its problems in icing conditions at relatively high altitude, or in cloud or something.

Not sure I buy the claims about maneuvering in Mars' atmosphere. Seems like the forces required to rotate a plane in flight would have to exist in the same proportion as to forces required to accelerate it perpendicular to it's velocity vector regardless of atmosphere of airspeed. Both would be linear functions of the atmospheric density and second order function of the "air"-speed.

Why not, A^2? Seems to me you buy the high TAS necessary to keep an aircraft aloft in the thin Martian atmosphere. Turn radius is r = v^2 / g (tan bank ang) so you can see why a high airspeed and "second order function" a/k/a V-squared leads to.... supersonic airliner handling.

Yes, I would expect the turn radius to be large. That ain't what the article claims. It claims: "if you turn, your plane rotates, but keeps moving in the original direction."

That's a whole lot different than having a large turn radius.

You recall that what causes an airplane's path to turn is the horizontal component of lift, right? So, how can whatever combination of density and airspeed produce sufficient lift to support the airplane, but fail to produce sufficient lift to *turn* the airplane?

A^2 --- Oh, right. Then we agree. The "plane rotates but keeps moving in the original direction" says more about Randall Munroe's phrasing than anything about X-plane.

I have a copy of X-plane played briefly on Mars. It was pretty boring - yes, very slow to turn, and impossible to land, with a ridiculously high landing speed. I think it shows 'normal' airplane handling ( in the supersonic oceanliner mode ) in a Martian atmosphere.

If you somehow "rotated the plane" in an attempt to turn it faster, I suspect it would stall &/or break up with aerodynamic overload.